Drugmakers are using an unusual tactic to compete in a new class of medication treating the 38 million Americans who have migraines

Since May, the FDA has approved three new drugs in a new class of preventive migraine medication: Aimovig, made by Amgen and Novartis; Ajovy, made by Teva; and Emgality, made by Eli Lilly.

Each one has a list price of $575 a month or $6,900 a year, with each drugmaker laying out its own approach to capturing the migraine market by offering the treatment for free.

The market for these treatments is massive. An estimated 38 million Americans have migraines. About 15 million of those people are eligible for these preventive treatments.

On Thursday, the third in a new class of preventative migraine medications got approved.

The drug, Emgality, came out at the same list price as the other two medications in the class – $575 per month, or $6,900 a year – along with a plan to provide the drug for free to commercially insured patients for up to a year.

And it’s not the only drug to offer up huge discounts in the first few months – and even years – of coming onto the market, with each drugmaker aiming to capture the migraine market.

The new drugs, taken as monthly or quarterly injections, aim to cut down on the number of migraine days patients experience.

About 15 million of those people are eligible for these preventive treatments.

Here’s a breakdown of each drug’s approach to owning the market:

Amgen and Novartis, Aimovig: $575 per month list price and two months of free samples, followed by a patient assistance program that provides up to a year of coverage if commercial insurance doesn’t cover it. For those with commercial insurance, there’s a $5 copay program that’s capped at $2,700 a year.

Teva, Ajovy: $575 per month list price and a savings card that lets patients access Ajovy for free until December 2019.

Lilly, Emgality: $575 per month list price, as well as starter kits in doctors’ offices. Lilly also plans to have a patient access program that provides up to 12 months of Emgality for free.

In recent years, when competing drugs, such as treatments for hepatitis C, enter the market, newcomers have undercut the list price of medications. That’s not the case with the preventive migraine treatments.

“We believe the market for the next year will be very contentious and net pricing could be substantially lower than the $6,900 list price,” Wells Fargo analyst David Maris said in a note Friday. There are still discounts drugmakers provide to middlemen in the form of rebates, which will likely be a competitive area for the three drugs.

For example, Wei-Li Shao, the vice president of Lilly’s neuroscience business, told Business Insider that the company is also in conversations with organizations responsible for paying for medications, such as pharmacy benefit managers, to strike up “value-based agreements” in which the drugmaker would get paid for a medication based on how well it reduces migraines in a particular patient.

For the drugmakers, providing the drug for free serves as a way to get access to more patients at the upstart. Because the treatments are preventative and migraines are a chronic condition, the expectation is that patients will be on the medication for a long enough time to make up for it, even if the drugmakers aren’t making money off of it for months after it comes on the market.

“We view this strategy as testament to the recognized long-term size/value of this largely prevalent pool of patients where we expect a significant degree of ‘stickiness’ once patients are on treatment with a specific agent as opposed to competing on price,” RBC Capital Markets analyst Kennen MacKay said in a note Friday.